Acidic esters of oxypropylated diamines



Patented May 25, 1954 2,679,519 ACIDIC ESTERS OF OXYPROPYLATED AMINES Melvin De Groote, University City, Mo., assignor to Petrolite Corporation,

ware

a corporation of Dela- No Drawing. Application May 14, 1951, Serial No. 226,337

9 Claims.

The present invention is a continuation-inpart of my co-pending applications Serial Nos. 104,802, filed July 14, 1949 (now abandoned), 109,620, filed August 10, 1949, and 107,382, filed July 28, 1949.

The present invention is concerned with certain new chemical products, compounds, or compositions which have useful application in various arts. It includes methods or procedures for manufacturing said new chemical products, compounds, or compositions, as Well as the products, compounds, or compositions themselves.

Complementary to the above aspect of the invention herein disclosed, is my companion invention concerned with the use of these particular chemical compounds, or products, as demulsifying agents in processes or procedures particularly adapted for preventing, breaking, or resolving emulsions of the water-in-oil type, and particularly petroleum emulsions. See my 00- pending application Serial No. 226,336, filed May 14, 1951, now Patent No. 2,626,923.

Said last aforementioned co-pending application, i. e., Serial No. 107,382, is concerned with high molal oxypropylation derivatives of monomeric polyamine compounds, with the proviso carbon atoms; (b) the initial polyamino reactant have a molecular weight of not over 1800 and at least a plurality of reactive hydrogen atoms; (0) the initial polyamino reactant must be watersoluble; (d) the oxypropylation end product must be water-insoluble; (e) the oxypropylation end product be within the molecular weight range of 2,000 to 30,000, on an average statisical (f) the solubility characteristics of the oxypropylation end product in respect to water must be substantially the result of the oxypropylation step; (9) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of 7 to 70; (h) the initial polyamino reactant must represent not more than 20%, by weight, of the oXypropylation end product on a statistical basis; (2') the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial polyamino reactant; (7) the polyamino reactant must contain at least one basic nitrogen atom; and (is) the nitrogen atoms are linked by a carbon atom chain.

Furthermore, in said aforementioned co-pending application it was pointed out that such hydroxylated materials obtained by oxypropylation could be reacted with dicarboxy acids such as diglycollic acid to yield valuable derivatives which. are satisfactory also for demulsification of petroleum emulsions.

The fractional esters herein described are obtained from a polycarboxy acid and a polyhyafter, the diamine derivative need only have a plurality of reactive hydrogen atoms, i. e., two or more.

The most suitable raw material is a phenylene diamine as such, and particularly metaphenylene diamine, on account of its cost, or such diamine after treatment with several moles of pound must be characterized by (at) having 2 amino nitrogen atoms; (b) free from any radical having 8 or more carbon atoms in an uninterrupted group; (0) must be water-soluble; and Hi) have a plurality of reactive hydrogen atoms preferably at least 3 or 4.

Needless to say, the most readily available reactant, to wit, metaphenylene diamine, has four reactive hydrogen atoms and this would still be true after reaction with ethylene oxide, for instance, l to 4 moles of ethylene oxide. However,

reaction with glycide would provide as many as 8 reactive hydrogen atoms, provided that the molal ratio was 4 to 1, i. e., 4 moles of glycide for one mole of diamine. On the other hand, if metaphenylene diamine were treated with a mole of an alkylating agent so as to introduce an alkyl radical such as methyl, ethyl, propyl, butyl, hexyl, heptyl, or the like, or an aryl radical such For obvious reasons, my choice is as follows:

(a) The use of metaphenylene diamine rather than any other phenylenediamine, primarily because this is the cheapest isomer available;

(12) Use of metaphenylene diamine after treatment with l to 5 moles of ethylene oxide, although a modestly increased amount of ethylene oxide can be used in light of what is said hereinafter; or

(c) The use of a derivative obtained from metaphenylene diamine after reaction with glycide, or a mixture of ethylene oxide and glycide.

#Since reaction of metaphenylene diamine with propylene oxide is invariably involved, and since this oxyalkylation step is substantially the same as the use of ethylene oxide or glycide, for purpose of brevity, future reference will be made to metaphenylene diamine, as illustrating a procedure, regardless of what particular reactant is selected. It is not necessary to point out, of course, that the substituted phenylenediamine, i. e., where an alkyl, alicyclic, aryl or alkyl group has been introduced, can be subjected similarly to reaction with ethylene oxide, glycide, or a combination of the two.

I also want to point out it is immaterial whether the initial oxypropylation step involves hydrogen attached to oxygen or hydrogen attached to nitrogen. The essential requirement is that it be a labile or reactive hydrogen atom. Any substituent radical present must, of course, have less than 8 uninterrupted carbon atoms in a single group.

More specifically, then, the present invention is concerned with certain hydrophile synthetic products; said hydrophile synthetic products being the acidic fractional esters derived by reaction between (A) a polycarboxy acid; and (B) high molal oxypropylation derivatives of monomeric diamino compounds, with the proviso that (a) the initial diamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (b) the initial diamino reactant have a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; the initial diamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2, to 30,000 on an average statistical basis; (I) acteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result of the oxypropylation step; (g) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of 'Z to '70; (h) the initial diamino reactant must represent not more than by weight, of the oxypropylation end product on a statistical basis; (2') the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial diamino reactant; (9) the nitrogen atoms are linked by a phenylene ring, and with the further proviso that the ratio of (A) to (B) be one mole of (A) for each hydroxyl radical present in (B).

Considerable work has been conducted on the oxypropylation of high molal compounds, or at least oxypropylation of low molal compounds having a multiplicity of yield high molal compounds. The starting materials may be fairly simple, such as ethylene glycol or propylene glycol; or they may be amines which are essentially derivatives of ammonia, or compounds having l or more points of reaction propylene diamine, higher polyamines, diglycerol, sorbitol, etc. In

other instances, amides and diamides have been Briefly stated, and this at the most can be only a summarization, when the molecular weight due to oxypropylation goes beyond 2,000 and frequently less, there is a wide difference between the theoretical molecular weight, based on completeness of reaction and the molecular weight, as determined by a hydroxyl number, or the equivalent. Unfortunately, the higher polyphenylenediamines have not been examined; and the results obtained in the case of phenylenediamine still suggest that the same forces are in points of reaction to effect as in these other comparable oxypropylations. For this reason, what is said hereinafter in the text immediately following, considers some of these factors, particularly from the standpoint of amides, higher polyalkylene amines, etc. Such data are included, for the reason that this presentation appears the best available to throw some light on the oxypropylation of the herein described reactant, to wit, a phenylenediamine. What has been said previously in regard to the materials herein described, and particularly with reference to fractional esters, may be and probably is an oversimplification, for reasons which are obvious on further examination. It is pointed out subsequently that, prior to esterification, the alkaline catalyst can be removed by addition of hydrochloric acid. Actually, the amount of hydrochloric acid added is usually sufficent and one can deliberately employ enough acid, not only to neutralize the alkaline catalyst, but also to neutralize the amino nitrogen atom or convert it into a salt. Stated another way, a trivalent nitrogen atom is concerted into a pentavalent nitrogen atom, i. e., a change involving an electrovalency indicated as follows:

wherein HX represents any strong acid or fairly strong acid such as hydrochloric acid, nitric acid, sulfuric acid, a sulfonic acid, etc., in which H represents the acidic hydrogen atom and X represents the anion. Without attempting to complicate the subsequent description further, it is obvious then that one might have esters or one might convert the esters into ester salts, as described. Likewise, another possibility is that, under certain conditions, one could obtain amides. The explanation of this latter fact resides in this observation. In the case of an amide, such as acetamide, there is always a question as to whether or not oxypropylation involves both amido nitrogen atoms so as to obtain a hundred percent yield of the dihydroxylated compound. There is some evidence, to at least some degree, that a monohydroxylated compound is obtained, under some circumstances, with one amido hydrogen atom remaining without change.

Another explanation which has sometimes appeared in the oxypropylation of nitrogen-containing compounds, particularly such as acetamide, is that the molecule appears to decompose under conditions of analysis and unsaturation seems to appear simultaneously. One suggestion has been that one hydroxyl is lost by dehydration and that this ultimately causes a break in the molecule in such a way that two new hydroxyls are formed. This is shown, after a fashion, in a highly idealized manner in the fol- In the above formulas the large X is obviously not intended to signify anything except the censhown. Such suggestion is of interest only because it may be a possible explanation of how an increase in hydroxyl value does take place which could be interpreted as a decrease in molecular This matter is considered subsequently in. th 'inal paragraphs of Part 2. This same situation seems to apply in the oxypropylation of at least some polyalkylene amines, and thus is of significance in the instant situation.

In the case of higher polyamines, there is evidence that all the available hydrogen atoms are not necessarily attacked, at least under comparatively modest oxypropylation conditions, particularly when oxypropylation proceeds temperature, as herein described, for instance, about the boiling point of Water. For instance, in the case of diethylene triamine there is some evidence that one terminal hydrogen atom only in each of the we end groups is first attacked by propylene oxide and then the hydrogen atom attached to the central nitrogen atom is attacked. It is quite possible that three long propylene oxide chains are built up before the However, analytical procedure is not entirely satisfactory, in some instances, in differentiating between reactive hydrogen atom attached to nitrogen and reactive hydrogen atom attached to oxygen.

In the case of triethylenetetramine the same situation seems to follow. One hydrogen atom on the two terminal groups is first attacked and then the two hydrogen atoms on the two intermedi te nitrogen atoms. Thus, four chains tend to build up and perhaps finally, if at all, the remaining two hydrogen atoms attached to the two terminal groups are attacked. In the case of tetraethylene each of the terminal groups is attacked first, then the three hydrogen atoms attached to the three intermediate nitrogen atoms, and then finally, if at all, depending upon conditions of oxypropylation, the two remaining terminal hydrogen atoms are attacked.

If this is the case it is purely a matter of speculation at the moment, because apparently there is no data which determines the matter completely under all conditions of manufacture, and one has a situation somewhat comparable to the acylation of moncethanolamine or diethanolamine, i. e., acylation can take place involving either the hydrogen atom attached to oxygen or the hydrogen atom attached to nitrogen.

It is unnecessary to add that what has been said in regard to polyethyleneamines, including ethylenediamine, also applies to polypropyleneamines, including propylenediamine.

As far as the herein described compounds are concerned, it would be absolutely immaterial except that one would have, in part, a compound which might be the fractional ester and might also represent an amide in which only one carboxyl radical of a polycarboxylated reactant was involved. By and large, it is believed that the materials obtained are obviously fractional esters, for reasons which are apparent in light of what has been said and in light of what appears here'- inafter.

However, in order to present the invention in its broadest aspect, it had best be re-stated as follows: The subject matter is concerned with certain hydrophile synthetic products; said bydrophile synthetic products being a cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives obtained by reaction bea polycarboxy acid; and

atoms;

initial diamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2,000 to 30,000 on an average statistical basis; (f) the solubility characteristics of the oxypropylation end product in 70; (h) the initial diamino reactant must repby Weight, of the oxypropylation end product on a statistical basis; (2') the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial diamino reactant;

droxyl radical present in (B).

Although the herein described products have a number of industrial applications, they are of particular value for resolving petroleum emulsions of the water-in-oil type that are of particular value for resolving petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the in my co-pending application Serial No. 226,336, filed May 14, 1951.

The new products are useful as wetting, deterage, coal washing waste water, and various trade wastes and the like; as germicides, insecticides,

propylation derivatives insofar that a cogeneric mixture is invariably obtained; and

Part 4 is concerned with derivatives valuable for various purposes, including demulsification but not specifically claimed in the instant application.

PART 1 For a number of well known reasons equipment, whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as, for example, 95 to 120 C. Under such circumstances, the pressure will be less than 30 pounds per square inch unless some special procedure is employed, as is sometimes the case, to wit, keeping an atmosphere of inert gas such as nitrogen in the vessel during the reaction. Such low-temperature-low-reaction rate oxypropylations have been described very completely in U. S. Patent No. 2,448,664 to H. R. Fife et al., dated September '7, 1948. Lowtemperature-low-pressure oxypropylations are particularly desirable where the compound being subject to oxypropylation contains one, two, or three points of reaction only, such as monohydric alcohols, glycols and triols.

The initial reactants in the instant application contain at least two reactive hydrogens, and for this reason, there is possibly less avantage in using low-temperature-oxypropylation, rather than high temperature oxypropylation. However, the reactions do not go too slowly, and this particular procedure was used in the subsequent examples.

Since low-pressure-low-temperature reaction speed oxypropylations require considerable time, for instance, 1 to 7 days of 24 hours each to complete the reaction, they are conducted as a rule whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic features:

(a) A solenoid-controlled valve which shuts off the propylene oxide in event that the temperature gets outside a predetermined and set range, for instance, 95 to 120 C.; and

(19) Another solenoid valve which shuts off the propylene oxide (or for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as 25 to 35 pounds. Otherwise, the equipment is substantially the same as is commonly employed for this purpose, where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit. continuous oxyallqlation, whether it be oxypropylation or oxyethylation. With certain obvious changes, the equipment can be used also to permit oxyalkylation involving the use of glycide where no pressure is involved except the vapor pressure of a solvent, if any, which may have been used as a diluent.

As previously pointed out, the method of using propylene oxide is the same as ethylene oxide. This point is emphasized only for the reason that the apparatus is so designed and constructed as to use either oxide.

The oxypropylation procedure employed in the preparation of the oxyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous, automatically-controlled procedure was employed. In this procedure the autoclave was a conventional autoclave made of stainless steel and having a capacity of approximately 15 gallons and a working pressure of 1,000. pounds gauge pressure. This pressure obviously is far beyond any requirement, as far as propylene oxide goes, uniess there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the con ventional devices and openings, such as the variable-speed stirrer operating at speeds from 50 R. P. M. to 500 R. P. 'M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide, to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as a cooling jacket, and preferably, coils in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water, and further equipped with electrical heating devices. Such autoclaves are, of course, in essence, small-scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations, an autoclave having a smaller capacity, for instance, approximately 3 liters in one case and about 1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, was achieved by the use of a separate container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gallon, or somewhat in excess thereof. In some instances, a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about 60 pounds was used in connection with the l5-gallon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight iced glass, thermometer, connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and. the autoclave were flexible stainless steel hose or tubing, so that continuous weighings could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc. Attention is directed again to what has been said previously in regard to automatic controls which shut oil the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxvpropylations become uniform, in that the reaction temperature was held within a few degrees of any selected point, for instance, if 105' C. was selected as the operating temperature, the maximum point would be, at the most, 110 C. or 112 0., and the lower point would be 95 or possibly 98 0. Similarly. the pressure was held at approximately 30 pound within a -pound variation one way or the other, but might drop to practically zero, especially where as xylene is employed. The speed comparatively slow, under such compared with oxyalkylations at merous reactions were conducted of reaction was conditions, as 200 C. Nuin which the time varied from one day (24 hours) up to three days 72 hours), for completion of the final member of a series. In some instances, the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxvpronylation is concerned. The minimum time recorded was about a 4-hour period in a single step. Reactions indicated as being complete in 7 or 8 hours may have been complete in a lesser period of time, in light of the automatic equipment employed. In the addition of propylene oxide, in the autoclave equipment, as far as possible, the valves were set so all the propylene oxide, if fed the first 5 hours of the 8-hour period or twothirds of any shorter period. This meant that if the reaction was interrupted automatically for a period of time for pressure to drop or temperature to drop the predetermined amount of oxide would still be added, in most instances, well within the predetermined time period. Sometimes where the addition was a comparatively small amount in an 8-hour period there would be an unquestionable speeding up of the reaction, by simply repeating the example and using 4, 5 or 6 hours instead of 8 hours.

When operating at a comparatively high temperature, for instance, between 150 to 200 C., an unreacted alkylene oxide such as propylene oxide, makes its presence felt in the increase in pressure or the consistency of a high pressure. However, at a low enough temperature it may happen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted, there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be, a sample must be withdrawn and examined for unreacted propylene oxide. One obvious procedure, of course, is to oxypropylate at for instance, at 140 to 150 C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards. the latter stages of reacno solvent such a modestly higher temperature,

cialize in autoclave equipment,

tion, the longer the time required to add a given amount of oxide. One possible exp-lanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower the molecular weight, the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature, even in large scale operations, as much as a week or ten days time may lapse to obtain some of the higher molecular weight derivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined were conventional including the gauges, check Valves and entire equipment. As far as I am aware, at lea t two firms, and possibly three, spesuch as I have are prepared to kind. Similarly, pilot plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkylations, particularly involving employed in the laboratory, and

should not be conducted except in equipment especially designed for the purpose.

Example 1a The particular autoclave employed was one with a capacity of gallons, or on the average of about pounds of reaction mass. The speed of the stirrer could be varied from to 350 R. P. M. The initial charge was 11 pounds of metaphenylene diamine. Since this product was not particularly alkaline, there was added one pound of caustic soda. The reaction pot was flushed out with nitrogen, the autoclave sealed, and the automatic devices adjusted for injecting 87.75 pounds of propylene oxide in a 6-hour period. It was injected at the rate of about 15 pounds or more, per hour.

The pressure regulator was set for a maximum of 35-37 pounds per square inch. However, in this particular step, and in all succeeding steps, the pressure never got over 3'7 pounds per square inch. In fact, this meant that the bulk of the reaction could take place, and probably did take place, at an appreciably lower pressure. This comparatively low pressure was the oxide, glycide, propylene oxide, etc.,'

result of the fact that considerable catalyst was weight and as to solubility of the reaction prodadded in the initial charge. All things conuct in water, xylene, and kerosene.

TABLE 1 Composition Before Composition at End M. w. M NlnX. Ex. by Hyd. g Prcs., Time, No. Amine Oxide Cata- Theo. Amine Oxide Cata- Deterlbs. sq. lll's. Amt, Amt, ly M Amt, Amt, lyst, min. in.

lbs. lbs. lbs. Wt. lbs. lbs. lbs. lo. 110 1.0 910 11.0 s7. 75 1.0 786 251mm 35-37 2a. 5. 70 45. 97 52 l, 785 5.10 so. 47 52 1, 108 250-255 25-37 4 3a- 2.90 40.40 .21 3,410 2. 00 81.49 .27 2, 000 250-255 35-31 I 5 4a.- 1.00 50.00 5,020 1.00 75. .15 3,300 1 sidered, the propylene oxide was added comparatively slowly, and more important, the selected temperature range was 250255 F. (moderately higher than the boiling point or water). The initial introduction ofpropylene oxide was not started until the heating devices had raised the temperature to a little above the boiling point of water. At the completion of the reaction, a sample was taken and oxypropylation proceeded, as in Example 20., immediately following.

Example 2a 52.5 pounds of reaction mass identified as Example la, and equivalent to 5.76 pounds of the polyamine, 45 pounds of propylene oxide, and .52 pound of caustic soda, were reacted with 43.5 pounds of propylene oxide. No additional catalyst was added. The conditions, as far as temperature and pressure were concerned, were the same as in Example 1a, preceding. The time required to add the oxide was 4 hours. It was added at a rate of about 12 or 13 pounds per hour. At the end of the reaction period, part of the mass was withdrawn and oxypropylation continued, as in Example 3a, immediately following.

Example 3a 49.75 pounds of reaction mass identified as Example 2a, preceding, and equivalent to 2.99 pounds of the polyamine, 46.49 pounds of propylene oxide, and .27 pound of caustic soda, were subjected to reaction with an additional pounds of propyleneoxide. The conditions, as far as temperature and pressure were concerned, were the same as in the two preceding examples. The time period was somewhat longer, to wit, 7 hours. The propylene oxide was added at the rate of about 6 pounds per hour. The slower rate was probably due to the lower catalyst content. At the completion of the reaction part of the reaction mass was withdrawn and the remainder subjected to a final oxypropylation step, as described in Example 4a, immediately following.

Emample 4a 52.5 pounds of reaction mass identified as Example 3a, preceding, and equivalent to 1.66 pounds of the polyamine, 50.69 pounds of propylene oxide, and .15 pound of caustic soda, were subjected to further oxypropylation with 25 pounds of propylene oxide. The conditions of reaction, as far as temperature and pressure were concerned, were the same as in the three preceding examples. The time required to add the 25 pounds of propylene oxide was 5 hours. It was added at the rate of about 6 pounds per hour.

What has been said herein is presented in tabular form in Table I, immediately following, with some added information as to molecular insoluble in water, soluble in xylene but insoluble in kerosene; Example 30. was insoluble in water, soluble in xylene, and dispersible in kerosene; and Example 411 was insoluble in water but soluble in both xylene and kerosene.

The final product, i. a, at the end of the oxypropylation step, was apt to be either a straw color, or sometimes it would have a more definite light reddish amber or a distinct dark amber tinge, and at times, even a deep red amber color. In the later stages the product was invariably water-insoluble and kerosene-soluble. This is characteristic of all the products obtained from the products herein described. Needless to say, if more ethylene oxide radicals were introduced into the initial raw material, the initial product is more water-soluble and one must go to higher molecular weights to produce waterinsolubility and kerosene-solubility, "for instance, molecular weights such as 8,000 to 10,000 or more on a theoretical basis, and 4,000 to 5,000, or even more, on a hydroxyl molecular weight basis. If, however, the initial diamino compound is treated with one or more or perhaps several moles of butylene oxide, then the reverse effect is obtained and it takes less propylene oxide to produce water-insolubility and kerosene-solubility. These products were, of course, slightly alkaline, due to the residual caustic soda employed. This would also be the case if sodium lnethylate were used as a catalyst.

Speaking of insolubility in water or solubility in kerosene, such solubility test can be made simply by shaking small amounts of the materials in a test tube with water, for instance, using 1% to 5% approximately based on the amount of water present.

Needless to say, there is no complete conversion of propylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular weight, based on a statistical average, is greater than the molecular weight calculated by usual methods on basis of acetyl or hydroxyl value. Actually, there is no completely satisfactory method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances, the acetyl value or hydroxyl value serves as satisfactorily as an index to the molecular weight as any other procedure, subject to the above limitations, and especially in the higher molecular weight range. If any difiiculty is encountered in the manufacture of the esters, as described in Part 2, the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl value. This matter has been discussed in the literature and is a matter of common knowledge and re- 13 quires no further elaboration. In fact, it is illustrated by some of the examples appearing in the patent previously mentioned.

PART 2 As pointed out previously, the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids, particularly tricarboxy acids like citric and dicarboxy acid such as adipic acid, phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacic acid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconic acid or anhydride, maleic acid or anhydride adducts, as obtained by the Diels-Alder reaction from products such as maleic anhydride, and cyclopentadiene. Such acids should be heat-stable so they are not d composed during esterifi ation. They may contain as many as 36 carbon atoms, as, for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarbcxy fatty acids, or unsaturated monocarboxy acids having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the anhydrides or any other obvious equivalents. My preference, however, is to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polycarboxy acids and glyocols, or other hydroxylated compounds, is Well known. In the present instance the hydroxylated compounds obtained as described in Part 1, preceding, contain nitrogen atoms, which, at the most, are only weakly basic. is question as to the stability of any hydrochloride produced, or any other similar salt produced under conditions of esterification. If salts were formed, then in reality, it would be the salt that would be converted into an ester. This is comparable to similar reactions involving esterification of triethanolamine. However, it is not believed that this enters into the instant compounds derived from phenylene diamine, in light of what has been said previously.

Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purpose or" economy, it is customary to use either the acid or the anhydride. A conventional procedure is employed. On a laboratory scale one can employ a resin pct of the kind described in U. S. Patent No. 2,499,370, dated March 7, 1950, to De Groote and Keiser, and particularly with one more opening to permit the use of a porous spreader, if hydrochloric acid gas is to be used as a catalyst. Such device or absorption spreader consists of minute Alundum thimbles which are connected to glass tube. One can add a sulfonic acid, such paratoluene sulfonic acid as a catalyst. There is some objection to this, because, some instances, there is some evidence that this acid catalyst tends to decompose or rearrange the oxypropylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as diglycollic acid, which is strongly acidic there is housed to add any catalyst. The use of hydrochloric acid gas has one advantage over paratoluene sulfonic acid, and that is that at the end of the reaction, it can be removed by flushing out with nitrogen, Whereas. there is no reasonably convenient means available of removing the paratoluene sulfonic acid or other sulfonic acid employed. If hydro- Thus, there chloric acid is employed, one need only pass the gas through at an exceedingly slow rate so as to keep the reaction mass acidic. Only a trace of acid need be present. I have employed hydrochloric acid gas, or the aqueous acid itself to eliminate the initial basic material. My preference, however, is to use no catalyst whatsoever and to insure complete dryness of the diol, as described in the final procedure just preceding Table 2.

The products obtained in Part 1, preceding, may contain a basic catalyst. As a general procedure, I added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand overnight. It is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water, the distillation stops. This preliminary step can be carried out in the flask to be used for esterification. If there is any further deposition of sodium chloride during the reflux stage, needless a second filtration may be required. In any event, the neutral or slightly acidic solution of the oxypropylated derivatives described in Part 1 is then diluted further with sufficient xylene, decalin, petroleum solvent, or the like, so that one has obtained approximatelya40 solution. To this solution there is added a polycarboxylated reactant, as previously described, such as phthalic anhydride, succinic acid or andride, no Water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional and have been so thoroughly described in the literature that further consideration will be limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if any, can be employed. For example, the oxyallzylation can be conducted in oxypropylation. Such oxypropylation end product can then be acidified with just enough concentrated hydrochloric acid to just neutralize the residual basic catalyst. To this product one amount of anhydrous sodium sulfate (sufiicient in quantity to take up any water that is present) and then subject the mass to centrifugal force so as to eliminate the hyand probably the sodium chloride formed. The clear, somewhat viscous, straw-colored to dark amber liquid so obtained may contain a small amount of sodium sulfate or sodium chloride, but, in any event, is perfectly acceptable for esterification in the scribed.

It is to be pointed out that the products here described are not polyesters in the sense that there is a plurality of both diamino radicals and acid radicals; the product is characterized by having only one diamino radical.

In some instances I have found that in spite of the dehydration methods employed above, that a mere trace of water still comes through and that this mere trace of water certainly interferes with the acetyl or hydroxyl value determination, at least when a number of. conventional pro.-

cedures are used and may retard esterification, particularly where there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred to use the following procedures: I have employed about 200 grams of the polyhydroxylated compound, as described in Part 1, preceding; I have added about 60 grams of benzene, and then refluxed this mixture in the glass resin pot, using a phase-separating trap until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily, this refluxing temperature is apt neighborhood of 130 to possibly 150 C. all this water or moisture has been removed, I also withdraw approximately 20 grams or a little less benzene and then add the required amount of the carboxy reactant and also about 150 grams of a high boiling aromatic petroleum solvent. These solvents are sold by various oil refineries, and, as far as solvent effect, act as if they were almost completely aromatic in character. 'Iypi cal distillation data in the particular type I have employed and found very satisfactory is the following:

I. B. P., 142 C. 50 ml., 242 C. ml., 200 C. 55 ml., 244? C. m1., 209 C. 60 ml., 248 C. ml., 215 C. 65 m1., 252 C. m1., 216 C. '70 ml., 252 C. ml., 220 C. '15 mL, 260 C. m1., 225 C. ml., 264 C. 35 ml., 230 C. m1., 270 C. 40 ml., 234 C. m1., 280 C. 45 ml., 237 C. ml., 307 C.

After this material i added, refluxing is continued, and of course, is at a higher temperature, to wit, about to C. If the carboxy reactant is an anhydride, needless to say, no water of reaction appears; if the carboxy reactant is an acid, water of reaction should appear and should be eliminated at the above reaction temperature. If it is not eliminated, I simply separate out another 10 or 20 cc. of benzene by means of the phase-separating trap, and thus, raise the temperature to or 190 C., or even to 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory, provided one does not attempt to remove the solvent subsequently except by vacuum disand provided. there is no objection to a little residue. Actually, when these materials are used for a purpose such as demulsification, the solvent might just as well be allowed to remain. If the solvent is to be removed by distillation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive solvent, such as decalin, or an alkylated decalin, which has a rather definite or close range boilin point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

However, in this series of derivatives involving phenylene diamine, I have preferred to use xylene, for the reason that it could be removed completely by distillation, particularly vacuum distillation. As a result, in the data immediately following, the only solvent that appears is Xylene. Any one of a number of other suitable solvents, however, would be equally satisfactory, as pointed out previously.

tillation,

TABLE 2 Poly- Polycarhoxy Reactent Carboxy Resctant (grs) Diglycollic Acid 94. 5 186 Aconitic Acid. 123. 0 202 Oxalic Acid 97. 0 187 Phthalic Anhydride... 100. 0 279 Maleic Anhydridc 104. 0 262 Citraconic Anhydridc. 112.0 209 Diglycollic Acid 65. 5 218 Aconitic Acid.. 87.0 209 Oxalic Acid 61. 5 222 Phthalic Anhydri c... 77.0 209 Maleic Anhydride 48. 0 202 Citraconic Anhydride. 53.0 202 Diglycollic Acid". 41. 5 202 Aconitic Acid. 54. 0 202 Oxalic Acid. 39. 2 205 Phthalic Anhydr 40. 6 190 Maloic Anhydrid 30.0 198 Oitraconic Anhydrid 34. 0 199 Diglycollic Acid 32. 3 200 Aconitic Acid 42.0 202 Oxalic Acid. 30. 8 212 Phthalic Anhydride... 37. 0 200 Maleic Anhydride 23. 7 199 Citraconic Anhydride. 27. 0

Amt Maximum Time of solver'lt Esterifica- Estcriil- Water rs) tion Temp, cation Out (cc.) e 0. (hrs) acceptable, attention should be following details: the hydroxyl or acetyl value of manner that is directed to the (a) Recheck the oxypropylated derivative and use a stoichiometrically equivalent amount of acid;

(b) If t size of the molecule increases and the reactive hydroxyl radical represents a smaller fraction of the entire molecule, more difiiculty is involved in obtaining complete esterification.

Even under the most carefully controlled conucts can contribute a substantial proportion of the final cogeneric reaction mixture. Various suggestions have been made as to the nature of propylene oxide or derivatives thereof, i. e., of an aldehyde, ketone, or allyl alcohol. In. some instances, an attempt to react the stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant for the reason that apparently reactive hydroxyl radicals are present than indicated by the hydroxyl value. Under such circumstances there simply a residue of the carboxylic reactant which can be removed by filtration, or, if d the esterification procedure can be repeated, using an appropriately reduced ratio of carboxylic reactant.

Even the determination of the hydroxyl value by conventional procedure leaves much to be desired, due either to the cogeneric materials previously referred to, or for that matter, the presence of any inorganic salts or propylene oxide. Obviously, this oxide should be eliminated.

The solvent employed, if any, can be removed from the finished ester by distillation, and particularly vacuum distillation. The final products or liquids are generally straw to dark amber or cosi-ty. They can be bleached with bleaching clays, filtering chars, and the like. However, for purpose of demulsification or the like, color. is not a factor and decolorization is not justified.

Inthe above instance I have permitted the solvents to remain present in the final reaction mass. In other instances, I have followed the same procedure, using decalin or a mixture of decalin, or benzene in the same manner and ultimately removed all the solvents by vacuum distillation. Appearances of the final products are much the as the oxypropylated products before esterification, and in some instances, were somewhat darker in color and had a reddish cast and perhaps were somewhat more viscous.

It is unnecessary to point out. of course, that what has been said herein is the same, regardless of whether the initial material is a polyhydroxylated compound or a compound containing a plurality of hydrogen atoms attached to nitrogen.

PART 3 In the hereto appended claims the demulsifying agent is described as an ester obtained from a polyhydroxylated material having at least two reactive hydrogens. If one were concerned with a monohydroxylated material or a dihydroxylated material, be able to write a formula which, in essence, would represent the particular product. However, in a more highly hydroxylated material the problem becomes increasingly more diificult for reasons which have already Gxypropylaticn invol es the same sort of variations as appear in preparing high molal polypropylene glycols. Propylene glycol has a secondary alcoholic radical and a primary alcohol radical. Obviously, then, polypropylene glycols could be obtained, at least theoretically, in which two secondary alcoholic groups are united or a procedure without ties of such mixture represent the contribution of the various indivi ual members of the mixture.

On a statistical basis, of course, 11 can be appropriately specified.

hydric reactant, a single formula and say that by following such procedure, one can readily obtain or or of such compound. However, in the case of at least pounds which appear in some of the probable mixtures, or can be prepared as components and mixtures which are manufactured conventionally.

Simply by way of illustration, reference is made to the co-pending application of De Groote, Wirtel and Pettingill, Serial No. 109,791, filed August 11, 1949 (now Patent 2,549,434, granted April 17, 1951).

However, momentarily referring again to a monohydric initial reactant, it is obvious that if one selects any such simple hydroxylated comfactory method,

polymer of the alkylene oxides, except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20, 30, 40, or 50 units. .If such compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide, it is well known that one does not obtain a single constituent, which, for the sake of convenience, may be indicated as RO(C2H4O) 30H. Instead, one obtains a cogeneric mixture of closely related homologues, in which the formula may be shown as the following, RO(C2H4O)11H, wherein 'n, as far as the statistical average goes, is 30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point where n may represent 35 or more. Such mixture is, as stated, a cogeneric, closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental Principles of Condensation Polymerization, by Flory, which appeared in Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisbased on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appear in cogeneric condensation products of the kind described. This means that from the practical standpoint, i. e., the ability to describe how to make the prodnot under consideration and how to re eat such production time after time without diificulty, it is necessary to resort to some other method of description, or else consider the value of n, inv formulae such as those which have appeared previously and which appear in the claims, as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value, based on the assumption of completeness of reaction.

This may be illustrated as follows: Assume that in any particular example the molal ratio of propylene oxide per hydroxyl is 15 to 1. In a generic formula 15 to 1 could be 10, 20, or some other amount and indicated by n. Referring to this specific case actually one obtains products in which n probably varies from to 20, perhaps even further. The average value, however, is 15, assuming, as previously stated, that the reaction is complete. The product described by the formula is best described also in terms of method of manufacture.

The significant fact in regard to the oxypropylated polyamines herein described is that in the initial stage they are substantially all watersoluble, for instance, up to a molecular weight of 1,500 or thereabouts. Actually, such molecular weight represents a mixture of some higher molecular weight materials and some lower molecular weight materials. The higher ones are probably water-insoluble. The product may tend to emulsify or disperse somewhat because some of the constituents, being a cogeneric mixture, are water-soluble but the bulk are insoluble. Thus, one gets emulsifiability or dispersibility as noted. Such products are invariably xylenesoluble, regardless of whether the original reactants were or not. Reference is made to what has been said previou ly in regard to kerosenesolubility. For example, when the gets somewhere past 4,000, or at approximately 5,000, the product is kerosenesoluble and water-insoluble. These kerosenesoluble oxyalkylation products are most desirable for preparing the esters. I have prepared hydroxylated compounds not only up to the theoretical molecular weight shown previously, 1. e., about 5,000, but also some which were twice this high. I have prepared them, not only from phenylenediamine, but also from oxyethylated or oxybutylated derivatives previously referred to. The exact composition is open to question, for reasons which are common to all oxyalkylation. It is interesting to note, however, that the molecular weights based on hydroxyl determinations at this point were considerably less, in the neighborhood of a third or a fourth of the value at maximum point. Referring again to previous data, it is to be noted, however, that over the range shown of kerosene-solubility, the hydroxyl molecular weight has invariably stayed at two-thirds or five-eighths of the theoretical molecular weight.

It becomes obvious, when carboxylic esters are prepared from such high molecular weight materials, that the ultimate esterification product again must be a cogeneric mixture. Likewise, it is obvious that the contribution to the total molecular weight made by the polycarboxy acid is small. By the same token, one would expect the effectiveness of the demulsifier to be comparable to the unesterified hydroxylated material. Remarkably enough, in many instances the molecular weight product is distinctly better.

PART 4 As pointed out previously, the final product obtained is a fractional ester having free carboxyl radicals. Such product can be used as an intermediate for conversion into other derivatives which are effective for various purposes, such as the breaking of petroleum emulsions of the kind herein described. For instance, such product can be neutralized. with an amine so as to increase its water-solubility such as triethanolamine, tripropanolamine, oxyethylated triethanolamine, etc. Similarly, such product can be neutralized with some amine which tends to reduce the water-solubility such as cyclohexylamine, benzylamine, decylamine, tetradecylamine, octadecylamine, etc. Furthermore, the residual carboxyl radicals can be esterified with alcohols, such as low molal alcohols, methyl, ethyl, propyl, butyl, etc., and also high molal alcohols, such as octyl, decyl, cyclohexanol, benzyl alcohol, octadecyl alcohol, etc. Such products are also valuable for a variety of purposes, due to their modified solubility. This is particularly true where surface-active materials are of value, and especially in demulsification of water-in-oil emulsion.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A hydrophile synthetic product which is the ester of (A) a polycarboxy acid with (B) a high molal oxypropylated monomeric diamino compound with the proviso that (a) the monomeric diamino compound be free from any radical having at least .8 uninterrupted carbon atoms and be composed of atoms selected from the class consisting of carbon, hydrogen, nitrogen and oxygen: (b) the monomeric diamino compound have a molecular weight of not over 800 and at least a theoretical plurality of reactive hydrogen atoms; (0) the 21 22 oxypropylated monomeric diamino compound 2. A product as in claim 1 in which the polyhave a molecular weight of 2,000 to 30,000 on an carboxy acid is a dicarboxy acid. average statistical basis; (12) the ratio of propyl- 3. A product as in claim 2 in which the monoene oxide per initial reactive hydrogen atom of meric diamino compound is a phenylene diamine. the monomeric diamino compound be within the 5 A p od ct s in claim 3 in which the y range of 7 to 70; (e) the monomeric diamino comene diamine is metaphenylenediamine.

pound represent not more than 20% by weight of 5. The product of claim 1, wherein the dicarthe oxypropylated monomeric diamino compound boxy acid is diglycollic acid.

on a statistical basis; (I) the preceding provisos 6. The product of claim 1, wherein the dicarbeing based on the assumption of complete re- 10 boxy acid is maleic acid.

action between the propylene oxide and the mono- 7. The product of claim 1, wherein the dicarmeric diamino compound; (9) the nitrogen atoms boxy acid is phthalic acid.

are linked by a phenylene radical; (h) the ratio 8. The product of claim 1, wherein the dicarof polycarboxy acid to oxypropylated monomeric boxy acid is citraconic acid. diamino compound being one mole of the former l5 9. The product of claim 1, wherein the dicarfor each reactive hydrogen atom of the latter; boxy acid is succinic acid. and (2') the polycarboxy acid be selected from the group consisting of acyclic and isocyclic dicarboxy No references cited canbon atoms. 

1. A HYDROPHILE SYNTHETIC PRODUCT WHICH IS THE ESTER OF (A) A POLYCARBOXY ACID WITH (B) A HIGH MOLAL OXYPROPYLATED MONOMERIC DIAMINO COMPOUND WITH THE PROVISO THAT (A) THE MONOMERIC DIAMINO COMPOUND BE FREE FROM ANY RADICAL HAVING AT LEAST 8 INTERRUPTED CARBON ATOMS AND BE COMPOSED OF ATOMS SELECTED FROM THE CLASS CONSISTING OF CARBON, HYDROGEN, NITROGEN AND OXYGEN; (B) THE MONOMERIC DIAMINO COMPOUND HAVE A MOLECULAR WEIGHT OF NOT OVER 800 AND AT LEAST A PLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THE OXYPROPYLATED MONOMERIC DIAMINO COMPOUND HAVE A MOLECULAR WEIGHT OF 2,000 TO 30,000 ON AN AVERAGE STATISTICAL BASIS; (D) THE RATIO OF PROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM OF THE MONOMERIC DIAMINO COMPOUND BE WITHIN THE RANGE OF 7 TO 70; (E) THE MONOMERIC DIAMINO COMPOUND REPRESENT NOT MORE THAN 20% BY WEIGHT OF THE OXYPROPYLATED MONOMERIC DIAMINO COMPOUND ON A STATISTICAL BASIS; (F) THE PRECEDING PROVISOS BEING BASED ON THE ASSUMPTION OF COMPLETE REACTION BETWEEN THE PROPYLENE OXIDE AND THE MONOMERIC DIAMINO COMPOUND; (G) THE NITROGEN ATOMS ARE LINKED BY A PHENYLENE RADICAL; (H) THE RATIO OF POLYCARBOXY ACID TO OXYPROPYLATED MONOMERIC DIAMINO COMPOUND BEING ONE MOLE OF THE FORMER FOR EACH REACTIVE HYDROGEN ATOM OF THE LATTER; AND (I) THE POLYCARBOXY ACID BE SELECTED FROM THE GROUP CONSISTING OF ACYCLIC AND ISOCYCLIC DICARBOXY AND TRICARBOXY ACIDS COMPOSED OF CARBON, HYDROGEN AND OXYGEN AND HAVING NOT MORE THAN 8 CARBON ATOMS. 